Gaugino Masses in Modular Invariant Supergravity

TL;DR

This paper calculates gaugino masses in string-derived supergravity models, emphasizing the role of modular invariance and quantum effects, and explores how matter fields influence these masses.

Contribution

It introduces a method using linear multiplet formulation to incorporate perturbative modular invariance in gaugino mass calculations from string models.

Findings

Quantum effects contribute to gaugino masses in observable sectors.

Matter fields coupling to Green-Schwarz terms significantly enhance gaugino masses.

The formalism relates to and clarifies previous supergravity calculations.

Abstract

We calculate gaugino masses in string-derived models with hidden-sector gaugino condensation. The linear multiplet formulation for the dilaton superfield is used to implement perturbative modular invariance. The contribution arising from quantum effects in the observable sector includes the term recently found in generic supergravity models. A much larger contribution is present if matter fields with Standard Model gauge couplings also couple to the Green-Schwarz counter term. We comment on the relation of our K\"ahler U(1) superspace formalism to other calculations.